Fin assembly

ABSTRACT

A fin assembly including a fin having a base portion, the base portion having at least one extension portion extending from the base portion, at least one extension portion mounting at least one engagement portion, at least one socket mount for substantially permanent inclusion in a watercraft to which the fin is to be mounted, the socket mounting having at least one opening corresponding with and complementary to the extension portion and engagement portion on the fin so that the at least one extension portion and engagement portion can be received in the respective openings; and a securing means for releasably securing the fin relative to the socket mount.

FIELD OF THE INVENTION

The present invention relates to watercraft and more particularly for fin assemblies which provide a secure attachment for removable fins.

This invention relates particularly to fin assemblies for surfboards and it will be convenient to hereinafter describe the invention with reference to this application. However it is to be clearly understood that the invention has broader application. For example it extends to other water craft such as sailing craft, paddle skis and surf skis and the like. For convenience such craft will be referred to collectively hereinafter as “boards”.

BACKGROUND ART

One of the prior inventions in this area is disclosed in U.S. Pat. No. 6,139,383 and that document contains a summary of the prior art systems and some of their problems. A portion of the Background Art section from U.S. Pat. No. 6,139,383 is reproduced here verbatim:

“Surf boards comprise broadly a body having a core of buoyant material, an upper ride surface for supporting a surfer and a lower surface which is received in the water. One or more fins are mounted on the lower surface thereof. Traditionally the fins have been permanently mounted to the body by being fibreglassed onto the body.

The disadvantage of permanently mounting a fin to a surfboard is that it cannot be easily removed and replaced when the fin is damaged. Further the fin cannot be easily removed from the board and replaced with another fin having different performance properties to enable experimentation with different fin types to occur. Further when transporting surfboards, the fin is relatively ungainly and consumes a large amount of space. Accordingly it would be advantageous in such situations to be able to remove the fin from the body of the board.

A removable fin assembly has been developed which is described in Australian patent 665804. This fin assembly comprises a fin having two thin rectangular tabs projecting outwardly from the base of the fin. Each such tab is received within a socket of a disc-like plug mounted in the lower surface of the body of the surfboard. The fin tabs are releasably locked in the plug by means of opposed fastening elements such as grub screws which clamp the tab. However this assembly has limited strength.

This fin assembly also has other shortcomings. For example this fin assembly requires precision work for it to be mounted on the body of the surfboard. This is because the two spaced plugs have to be spaced a precise distance apart to enable them to mate with the two fin attachment elements in order to provide ease of attachment and release of the fin means. In addition a number of grub screws is used to secure each fin and thus it is time consuming to mount a fin to the board.

A further feature of the fin assembly is a resin plug which extends from the bottom of the body attachment element through the core of the body to the upper ride surface of the surfboard. This resin plug provides some support for the fin attachment element to assist in mounting it in stable fashion on the body of the surfboard. However after use this resin plug tends to work through the fibreglass coating on the ride surface of the surfboard. This is unsightly and causes water leakage into the inner core of the board. The so formed discontinuity in the ride surface may injure the rider.

Another disadvantage associated with such arrangements is that the fin body projects forwardly and rearwardly beyond the tabs and in use these portions of the fin body are positioned in abutting relationship with or adjacent to the lower surface.

In order to be useful in the art, the fin assembly should be easy to install, relatively inexpensive to manufacture and be securely fixed when desired but easy to remove when desired.

It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

SUMMARY OF THE INVENTION

The present invention is directed to a fin assembly, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.

In one form, the invention resides in a fin assembly including a fin having a mounting base portion, the mounting base portion having at least one fixing portion, the at least one fixing portion including at least one extension portion extending from the mounting base portion; each at least one extension portion mounting at least one engagement portion, at least one socket mount for permanent inclusion in a watercraft to which the fin is to be mounted, the socket mounting having at least one opening corresponding with and complementary to the at least one fixing portion on the fin so that the at least one fixing portion can be received in the respective openings; and a securing means for releasably securing the fin to the socket mount.

In a further form, the invention resides in a fin assembly including a fin having a base portion, the base portion having at least one extension portion extending from the base portion, at least one extension portion mounting at least one engagement portion, at least one socket mount for substantially permanent inclusion in a watercraft to which the fin is to be mounted, the socket mounting having at least one opening corresponding with and complementary to the extension portion and engagement portion on the fin so that the at least one extension portion and engagement portion can be received in the respective openings; and a securing means for releasably securing the fin relative to the socket mount.

As stated above, the fin assembly of the present invention is particularly well adapted to use on surfboards but may be used on any finned watercraft. The fin assembly normally includes a fin and a mounting assembly for the fin in order to removeably attach the fin to the board. One or more fin assemblies may be provided on the same board. For example, a known type of surfboard is provided with three fins which are laterally spaced across the width of the rear of the board and the central fin is located behind the outer two fins.

The present invention is particularly well adapted to attaching fins which are to have a fixed orientation when secured to the board but a similar system, with a relatively minor modification well within the purview of the person having ordinary skill in the art, may be used for pivoting or rotatable fins.

The present invention is a fin assembly including a fin. The fin may be of any configuration suitable for use as a fin. The fin will typically have a tip and opposed major surfaces extending from the tip. The fin will typically be manufactured of a rigid material such as fibreglass, plastic or similar but metal fins have been used in the past. Obviously given the conditions in which the fin is to be used, a corrosion resistant material is preferred so metals are not generally used. The fin will typically have a leading edge and a trailing edge, based on the direction of travel in ordinary usage.

The fin of the preferred embodiment includes a mounting base portion. The fin will normally have a base edge generally opposite the tip end of the fin. The base edge is usually substantially planar and perpendicular to the leading and trailing edges of the fin, or the “fin plane”. It is to be noted at this point that fins having base edges which are at angles other than perpendicular to the fin plane are known and the assembly of the present invention can be used equally to attach fins of that type.

The base edge of the fin will normally be configured to abut an outer, lower surface of the watercraft when properly and securely attached to the watercraft.

The mounting base portion of the fin of the preferred embodiment has at least one fixing portion adapted to facilitate fixing of the fin relative to a board. The at least one fixing portion usually includes one or more male portion to be received and retained in the opening in the socket mounts of the assembly.

There may be a single fixing portion used according to the invention but preferably, more than one will be used as this allows a more even and superior spreading of load. Preferably a pair of fixing portions will be used, a first fixing portion located towards the leading edge end of the base edge and a second fixing portion located towards the trailing edge end of the base edge. Each of the fixing portions will typically be spaced from the respective leading and trailing edge.

It is also to be noted at this juncture that a single fixing portion can be used, but is less preferred than a plurality of fixing portions.

The fixing portion of the preferred embodiment includes at least one extension portion extending from the mounting base portion, each at least one extension portion mounting at least one engagement portion.

The extension portion may extend substantially perpendicularly to the fin plane, although a coplanar extension portion is preferred. It is also preferred that the extension portion may be integrally formed with the fin itself and generally will be formed at the same time and of the same materials as the fin itself.

Each extension portion will preferably be substantially rectangular although any shape can be used. Providing rectangular extension portions allows the extension portions to be formed by removing portions of a fin from the mounting base portion.

The extension portions usually extend from the base edge of the fin and are typically of similar width to the fin itself. The extension portions may be slightly narrower than the width of the fin as this may provide a shoulder portion to more effectively position the fin adjacent the underside of the watercraft. The extension portion may be termed a “tab” portion.

Each extension portion includes at least one engagement portion. Each at least one engagement portion is preferably mounted relative to the extension portion to extend at an angle to the extension portion and/or the fin. It is preferred that the engagement portion extends substantially perpendicularly from the extension portion as this will provide the maximum operable length to be engaged by the securing means.

The engagement portion may be mounted to extend on one lateral side of the extension or tab portion or on both lateral sides thereof. The engagement portion may extend substantially in the same plane as the extension portion forwardly or rearwardly of the extension portion or in both directions.

According to a preferred embodiment, the engagement portion may be separately formed to the engagement portion or alternatively may be formed integrally therewith to reduce the number of components of the fin assembly or to improve strength of the assembly. The extension portion can be provided with an opening therein or therethrough and the engagement portion can then be located in or through the opening. Where this method is used, the engagement portion may be fixed in the opening using any suitable method but adhesive or similar is preferred. A portion of the engagement portion may be threaded in order to engage with the extension portion.

Each of the engagement portions may be an elongate member and be substantially rod-like or pin-like. The engagement portion may be rectangular prism shaped or cylindrical or any other cross-sectional shape.

The fin assembly of the invention also includes at least one socket mount for permanent inclusion in a watercraft to which the fin is to be mounted, each socket mounting having at least one opening corresponding with and complementary to, the at least one fixing portion on the fin so that the at least one fixing portion can be received in the respective openings and releasably secured therein.

The fin assembly includes at least one socket mount for permanent inclusion in a watercraft to which the fin is to be mounted, the socket mounting having at least one opening corresponding with and complementary to the at least one fixing portion on the fin so that the at least one fixing portion can be received in the respective openings. These socket mounts may be referred to as “plugs”.

Each of the plugs preferably has a substantially cylindrical body moulded from suitable material such as polycarbonate. An outer cylindrical surface of the plug may be provided with circumferential rib portions to allow a more secure fixing to the board.

One or more locating lugs may also be provided. Where provided, the locating lugs may be sized to correctly position the plugs for use.

Each plug is provided with a substantially rectangular main slot opening to its upper circular face. The main slot opening will typically be located parallel to the length of the board and the plugs may be secured to the board in a location to achieve this.

A laterally extending slot opening is also preferably provided and this slot opening is preferably formed in conjunction with the main slot opening to form a T-shaped opening. The shape and configuration of the opening is shaped and sized to correspond to the shape and configuration of the extension and engagement portions of the fixing portion of the fin.

Each plug is also provided with an obliquely extending opening or tapped hole, extending from the face and intersecting the laterally extending slot opening, preferably at a lower portion of the laterally extending slot opening as this is the location of the engagement portion of the fixing portion of the fin when properly located. This hole preferably receives a securing means, most preferably a grub screw or similar to secure the engagement portion in the laterally extending slot opening and therefore secure the fin to the board. When properly used, the grub screw will typically overlie and abut the engagement portion of the fixing portion of the fin to retain it therein. The obliquely extending opening or tapped hole may extend either forwardly or rearwardly in the plug.

The plugs are preferably fixed, by means of polyester resin or other adhesive chosen for compatibility with the materials of the board and the plugs, in circular holes drilled in the board. These holes may be formed at any convenient stage in the manufacture of the board, but in particular they may be drilled after the glassing of the board, thereby simplifying the finishing steps in board manufacture. Although it is not essential that the holes be circular, this is preferred, because a hand drill can be used, and in conjunction with suitable jigs and templates the holes can be quickly and accurately placed in the board.

In the preferred form, two plugs are provided for each fin, and each fin is provided with a pair of fixing portions extending downwardly from the base of the fin and spaced apart the same distance as the plugs. These fixing portions are dimensioned for an interference fit in the slots of the plugs. By forcing the fixing portions into the slots, the fin is mounted on the board, and then locked in place by driving home the grub screw so that it bears against the engagement portion located in the laterally extending slot opening. The open end of the hole in the plug into which the grub screw is driven may be closed with a core plug pressed into the hole so that its upper face is flush with the surface of the plug.

In this way a fin fixing is achieved which combines simplicity of manufacture with lightness and strength, and provides greater ease of assembly and disassembly than the use of a fin box. Since the plugs present an uninterrupted surface flush with that of the board, and may further be sanded and finished along with the board surface, the final finishing steps of board manufacture may be carried out without the fins in place to obstruct the operator or the equipment, thereby reducing costs and enabling better finishes to be obtained, and the hydrodynamic deficiencies of the prior art arrangements can be avoided.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention will be described with reference to the following drawings, in which:

FIG. 1 is a perspective view of a preferred embodiment of a fin assembly with a pair of socket mounts for attaching a fin.

FIG. 2 is a detailed perspective view of the preferred embodiment illustrated in FIG. 1.

FIG. 3 is a side elevation view of the preferred embodiment of fin assembly as illustrated in FIG. 1 with one socket mount engaged and the other free.

FIG. 4 is a front elevation view of the preferred embodiment of fin assembly as illustrated in FIG. 3 with both socket mounts free.

FIG. 5 is a detailed, partially sectional view of the fin assembly illustrated in FIG. 1.

FIG. 6 is a perspective view of a socket mount according to a preferred embodiment of the present invention.

FIG. 7 is a side elevation view of the socket mount as illustrated in FIG. 6.

FIG. 8 is an end elevation view of the socket mount as illustrated in FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

According to a preferred aspect of the invention, a fin assembly is provided.

The fin assembly includes a fin 10 as illustrated in FIGS. 1 to 5 in particular. The fin has a tip 11 and opposed major surfaces 12 extending from the tip 11. The fin 10 is manufactured of a rigid material such as fibreglass, plastic or similar The fin 10 has a leading edge 13 and a trailing edge 14, based on the direction of travel in ordinary usage.

The fin of the illustrated embodiment has a mounting base edge 15, the mounting base edge 15 having a pair of fixing portions 16. Each fixing portion 16 includes an extension portion 17 extending from the mounting base edge 15 of the fin 10 and an engagement portion 18.

The fin 10 has a base edge 15 generally opposite the tip 11 of the fin 10. The base edge 15 is substantially planar and perpendicular to the leading 13 and trailing 14 edges of the fin 10, or the main “fin plane”.

The base edge 15 of the fin 10 is configured to abut an outer, lower surface of the watercraft when properly and securely attached to the watercraft.

A pair of fixing portions 16 are used according to the illustrated embodiment, a first fixing portion located towards the leading edge end of the base edge 15 and a second fixing portion located towards the trailing edge end of the base edge 15. Each of the fixing portions 16 are spaced from the respective leading 13 and trailing 14 edges.

The extension portion 17 of the illustrated embodiment extends from the base edge 15 of the fin 10 in the same plane as the fin plane. The extension portion 16 is integrally formed with the fin 10 itself and is generally formed at the same time, and of the same materials, as the fin 10 itself.

Each extension portion 17 is substantially rectangular although any shape can be used. Providing rectangular extension portions as illustrated allows the extension portions 17 to be formed by removing portions of a fin from adjacent the mounting base edge 15.

The extension portions 17 are typically of similar width to the fin 10 itself. The extension portions may be slightly narrower than the width of the fin as this may provide a shoulder portion to more effectively position the fin adjacent the underside of the watercraft.

Each extension portion 17 includes at least one engagement portion 18. Each engagement portion 17 is mounted relative to the extension portion 17 to extend at an angle to the extension portion 17 and/or the fin 10. According to the illustrated embodiment, each engagement portion 18 extends substantially perpendicularly from the extension portion 17 as this will provide the maximum operable length to be engaged by the securing means.

The engagement portion 18 of the illustrated embodiment is mounted to extend on one lateral side of the extension portion 17.

According to the illustrated embodiment, the engagement portion 18 is separately formed to the engagement portion 17. The extension portion 17 is provided with an opening therein and the engagement portion can then be located in the opening. Where this method is used, the engagement portion 18 is fixed in the opening using any suitable method but adhesive or similar is preferred. A portion of the engagement portion 18 can be threaded in order to engage with the extension portion.

Each of the engagement portions 18 is an elongate member and are substantially rod-like or pin-like.

The fin assembly of the illustrated embodiment also includes a socket mount 19 or plug as illustrated in FIGS. 6 to 8 in particular for permanent inclusion in a watercraft to which the fin 10 is to be mounted, each socket mount 19 having an opening corresponding with and complementary to, the shape of the fixing portion 16 on the fin 10 so that the fixing portion 16 can be received and releasably secured in the respective openings. These socket mounts may be referred to as “plugs”.

Each of the plugs 19 has a substantially cylindrical body moulded from suitable material such as polycarbonate. An outer cylindrical surface of the plug may be provided with circumferential rib portions 20 to allow a more secure fixing to the board.

One or more locating lugs 21 are also provided and are sized to correctly position the plugs 19 for use.

Each plug 19 is provided with a substantially rectangular main slot opening 22 to its upper circular face 23. The main slot opening 22 is located parallel to the length of the board and the plugs 19 are secured to the board in a location to achieve this.

A laterally extending slot opening 24 is also provided and this slot opening 24 is formed in conjunction with the main slot opening 22 to form a T-shaped opening. The shape and configuration of the opening is shaped and sized to correspond to the shape and configuration of the extension 17 and engagement 18 portions of the fixing portion 16 of the fin 10.

Each plug 19 is also provided with an obliquely extending opening or tapped hole 25, extending from the face 23 and intersecting the laterally extending slot opening 24 at a lower portion of the laterally extending slot opening 24 as this is the location of the engagement portion 18 of the fixing portion 16 of the fin 10 when properly located. This hole 25 receives a securing means, most preferably a grub screw 26 or similar to secure the engagement portion 18 in the laterally extending slot opening 24 and therefore secure the fin 10 to the board. When properly used, the grub screw 26 overlies and abuts the engagement portion 18 of the fixing portion 16 of the fin 10 to retain it therein.

The plugs 19 are fixed, by means of polyester resin or other adhesive chosen for compatibility with the materials of the board and the plugs, in circular holes drilled in the board. These holes may be formed at any convenient stage in the manufacture of the board, but in particular they may be drilled after the glassing of the board, thereby simplifying the finishing steps in board manufacture. Although it is not essential that the holes be circular, this is preferred, because a hand drill can be used, and in conjunction with suitable jigs and templates the holes can be quickly and accurately placed in the board.

In the illustrated form, two plugs 19 are provided for each fin 10, and each fin 10 is provided with a pair of fixing portions 16 extending downwardly from the base of the fin 10 and spaced apart the same distance as the plugs 19. These fixing portions 16 are dimensioned for an interference fit in the openings of the plugs 19. By forcing the fixing portions 16 into the openings, the fin 10 is mounted on the board, and then locked in place by driving home the grub screw 26 so that it bears against the engagement portion 18 located in the laterally extending slot opening 24. The open end of the tapped hole 25 in the plug 19 into which the grub screw 26 driven may be closed with a core plug pressed into the hole so that its upper face is flush with the surface of the plug 19.

In this way a fin fixing is achieved which combines simplicity of manufacture with lightness and strength, and provides greater ease of assembly and disassembly than the use of a fin box. Since the plugs present an uninterrupted surface flush with that of the board, and may further be sanded and finished along with the board surface, the final finishing steps of board manufacture may be carried out without the fins in place to obstruct the operator or the equipment, thereby reducing costs and enabling better finishes to be obtained, and the hydrodynamic deficiencies of the prior art arrangements can be avoided.

In the present specification and claims (if any), the word “comprising” and its derivatives including “comprises” and “comprise” include each of the stated integers but does not exclude the inclusion of one or more further integers.

Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations. 

1. A fin assembly including a fin having a base portion, the base portion having at least one extension portion extending from the base portion, at least one engagement portion with an abutment shoulder of lesser height than the at least one extension portion extending from the at least one extension portion, at least one socket mount for substantially permanent inclusion in a watercraft to which the fin is to be mounted, the socket mounting having at least one opening corresponding with and complementary to the extension portion and engagement portion on the fin so that the at least one extension portion and engagement portion can be received in the respective openings; at least one opening for receiving a securing means; and at least one securing means for releasably securing the fin relative to the socket mount by abutting the abutment shoulder of the at least one engagement portion.
 2. A fin assembly according to claim 1 wherein at least one extension portion and at least one engagement portion form a fixing portion to be received and retained in the at least one opening in a socket mount.
 3. A fin assembly according to claim 1 wherein the fin has a tip, a base edge and opposed major surfaces extending from the tip to the base, a leading edge and a trailing edge, based on the direction of travel in ordinary usage.
 4. A fin assembly according to claim 3 wherein the base edge of the fin is configured to abut an outer, lower surface of the watercraft when properly and securely attached to the watercraft.
 5. A fin assembly according to claim 4 wherein a pair of fixing portions are provided, a first fixing portion located spaced from the leading edge end of the base edge and second fixing portion spaced from the trailing edge end of the base edge.
 6. A fin assembly according to claim 1 wherein each extension portion is coplanar with the fin.
 7. A fin assembly according to claim 1 wherein the extension portion is integrally formed with the fin.
 8. A fin assembly according to claim 3 wherein the extension portions extend from the base edge of the fin and are narrower than the width of the fin to provide a shoulder portion to more effectively position the fin adjacent the underside of the watercraft.
 9. A fin assembly according to claim 1 wherein the at least one engagement portion is mounted relative to the extension portion to extend at an angle to the extension portion.
 10. A fin assembly according to claim 9 wherein the engagement portion extends substantially perpendicularly from the extension portion.
 11. A fin assembly according to any one of the preceding claims wherein the at least one engagement portion is mounted to extend on one lateral side of the extension portion.
 12. A fin assembly according to claim 1 wherein each of the engagement portions includes an elongate member.
 13. A fin assembly according to claim 1 wherein each of the socket mounts has a substantially cylindrical body with an outermost face when mounted relative to a watercraft.
 14. A fin assembly according to claim 1 wherein the socket mount includes at least one locating lug to assist with locating the socket mount on the watercraft.
 15. A fin assembly according to claim 13 wherein each socket mount is provided with a substantially rectangular main slot opening to the outermost face.
 16. A fin assembly according to claim 15 wherein the main slot opening is located parallel to the length of the watercraft.
 17. A fin assembly according to claim 15 further including a laterally extending slot opening formed in conjunction with the main slot opening to form a T-shaped opening.
 18. A fin assembly according to claim 17 further including an obliquely extending opening extending from the uppermost face and intersecting the laterally extending slot opening to engage the engagement portion of the fin when properly located.
 19. A fin assembly according to claim 18 wherein the obliquely extending opening is adapted to receive a removable securing means to secure the engagement portion in the laterally extending slot opening and therefore secure the fin to the board.
 20. A fin assembly according to claim 18 wherein the open end of the obliquely extending opening in the socket mount into which the securing means is received is closed with a core plug pressed into the hole so that its upper face is flush with the surface of the plug.
 21. A fin assembly including a fin having a base portion, the base portion having at least one fixing portion, the at least one fixing portion including at least one extension portion extending from the mounting base portion; each at least one extension portion mounting at least one engagement portion, at least one socket mount for permanent inclusion in a watercraft to which the fin is to be mounted, the socket mounting having at least one opening corresponding with and complementary to the at least one fixing portion on the fin so that the at least one fixing portion can be received in the respective openings; and a securing means for releasably securing the fin to the socket mount.
 22. A fin assembly according to claim 21 wherein the fin has a tip, a base edge and opposed major surfaces extending from the tip to the base, a leading edge and a trailing edge, based on the direction of travel in ordinary usage, and further including a pair of fixing portions, a first fixing portion spaced from the leading edge end of the base edge and a second fixing portion spaced from the trailing edge end of the base edge. 